When repeated and prolonged access to the vascular system is required, it is often impractical and dangerous to insert and remove a needle for each session. Thus, patients are often fitted with semi-permanent catheters to facilitate vascular access and reduce discomfort.
When not in use, these semi-permanent catheters may be sealed, for example, by valves such as Pressure Actuated Safety Valves (PASV) which open only when fluid pressure exceeds a preselected threshold pressure. PASV's often include a slitted membrane with edges that separate from one another to open the valve only when fluid pressure applied thereto exceeds a threshold level and which are drawn together to seal the valve whenever the pressure falls below this threshold level.
In addition to typical fluid infusion and withdrawal procedures, certain patients require power injections of fluids to, for example, perform CT and/or MR studies. Using the same peripherally inserted central catheter (PICC) for the typical infusion/withdrawal procedures as well as the power injections simplifies these procedures. However, as power injections require considerably higher flow rates and pressures than most other procedures, using the same PICC for power injections subjects the PICC to stress levels which are not sustainable by conventional PASV's. Some recent designs of high flow membranes for PASV's have been found suitable for power injection including, for example, U.S. Published Patent Application No. 20050043703 to Greg Nordgren (“the '703 application), which is hereby incorporated by reference in its entirety. The '703 application describes conical, high flow rate, multi-slit membranes for PASV's.